Influence of Texture on Bendability of Cu–Ni–Si Alloys

抄録

The influence of texture on the bendability in Cu–Ni–Si alloys was examined by using an age-hardened polycrystalline strip with various recrystallization textures. In multiple samples manufactured by adjusting conditions of rolling and heat treatment, the Cube orientation {100}<001>, the RD-rotated Cube orientation {012}<100>, the BR orientation {362}<853> and the R(S) orientation {231}<346>, which are the representative recrystallization textures of FCC metals, developed up to 40% in respective area fractions. The bendability was clearly dependent on texture. The sample that had a strongly developed Cube orientation showed the best bendability with respect to both the good and bad ways (GW, BW) in bending. In comparison, the samples in which the BR and the R orientations developed showed poor GW bendability. The sample having a comparably random orientation showed poor GW and BW bendability. The shape of the cracks generated by bending was linear, and these cracks developed in a direction about 40 degrees from the surface. Further, they developed along shear bands, and this result was confirmed by the EBSD measurement. Therefore, the cause of cracking resulting from bending was shear bands. The correlation between the good bendability and a low average Taylor factor was confirmed. More uniform deformation by crystalline slips through texture control was effective for restraining the shear bands, i.e., for obtaining excellent bendability.